Based on the information you have given I think the system is working as designed. I would look at the overall AC load in your coach before blaming the control unit.
I have attached the service manual for my system and by the sound of it they are similar if not alike. It should help you with understanding the issue.
Intellitec Environmental Control Panel.pdf
I would look at the overall AC system starting with the shore power connector to be sure it is clean, free of arcing damage, and the other connections are not corroded. Also check on how much of your 30 amps are being used at on time. Case in point at the campground I'm at now I tried both AC's but only the rear compressor would run with the front in "SHED" mode until I turned off the water heater. Once I shed the system of the amperage draw from the heater both AC's worked fine. So, even though I'm connected to the 30 amp outlet the CG may not be able to supply all 30 amps. If it is less, as I suspect with my example, then the system will divert amperage where needed until the load is reduced and amperage is available for both AC units.
Hope this helps.